Questions tagged [storage]
The storage tag has no usage guidance.
52
questions
16
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8answers
5k views
Why we still need Short Term Memory if Long Term Memory can save temporary data?
If RAM is a short term memory and SSD is a long term memory, why don't microarchitecture of computer nowadays use SSD or another long term memory for saving temporary data like hidden variable for ...
1
vote
1answer
43 views
Why did the concept of “write-protecting” not carry over from floppy disks to USB memsticks and especially external USB HDDs? [closed]
Many times, I've wished to plug in my backup hard disks into my PC without the risk of any of the data being deleted, overwritten, or modified in any manner. Purely for "inspection" and ...
1
vote
1answer
48 views
Is ROM primary memory or secondary memory?
According to this picture ROM is classified under Main Memory , but isn’t ROM a secondary storage because it’s external and non volatile ?
Any clarification with reference links will be highly ...
1
vote
1answer
33 views
Fair assignment of storage for multiple writers (load balance)
I'm trying to optimize a system with a better algorithm for allocating storage. The system has 'N' writer processes and 'M' disks. (N < 30, M < 10. N can change, M is constant).
Any process can ...
0
votes
0answers
54 views
Does writing more data to disk consume more energy than writing less?
As the title says, I am wondering if writing more data (i.e. larger files) to disk (e.g. Tablet SSDs) will consume more energy than smaller files.
My expected answer is "yes, because larger files ...
2
votes
1answer
53 views
Course teaching time complexities in real life systems
Having mis-read What course in CS deals with the study of RAM, CPU, Storage? I now wonder what course in CS deals with time and space complexities including GPUs, CPU caches in multiple levels, seek ...
5
votes
2answers
1k views
What course in CS deals with the study of RAM, CPU, Storage?
I watched the Crash Course playlist of Computer Science. It was teaching about RAM, CPU, Storage etc but I felt it was way too fast and only people who have studied the course first hand understood it ...
1
vote
0answers
27 views
Does Nand Flash Type Affect the Read Latency Based on Page Content?
In general, we have these types of NAND flash cells: SLC, MLC, TLC, and QLC. Since MLC flash cells can store 2 bits, the content of the cell can be 00, 01, 10, or 11 which are detected using different ...
0
votes
2answers
4k views
Difference between Sequential ,Direct and Random acess with their acess time
I'm stuck on a point while reading about these different accessing methods. As per author.
Sequential access
Memory is organized into units of data, called records.Access must be made in a ...
1
vote
0answers
18 views
Why do we need volume as an abstraction on top of partition?
I'm curious about what do we need volume as an abstraction on top of hardware partition? What problem it tries to solve? What is the limitation of this concept?
1
vote
0answers
96 views
Regarding Amdahl's balanced system law
One of the paper titled "Rules of Thumb in Data Engineering" (Jim Gray et. el.) mentions some calculations based on Amdahl's balanced system law.
Link to paper: https://www.microsoft.com/en-us/...
5
votes
1answer
2k views
Why does RAID-5 require an additional disk for parity blocks?
I know that RAID-5 consists of block-level striping across multiple disks, but using an additional parity-check block on each disk .. and that at least two disks are required for striping.
And it's ...
2
votes
1answer
227 views
Page cache and its relationship to page table
I was reading about the page cache Page cache - the cache in memory for files, but I couldn't find the answer to my question. Does the page table have anything to do with, or maintain any entries, for ...
2
votes
1answer
324 views
What exactly is a “binary file”?
I suspect this may be more of a concept / theory question, but, I haven't been able to wrap my brain around what exactly a binary file is.
I've read links such as the below:
https://en.wikipedia.org/...
1
vote
0answers
27 views
How extended logical blocks are mapped to physical device pages?
I'm reading "Decibel: Isolation and Sharing in Disaggregated Rack-Scale Storage" (PDF). On page 6, the author illustrates the concept of "Extended Logical Block"), which is similar to "Data Integrity ...
5
votes
1answer
249 views
Could a standardized ternary system be more efficient than the binary system? [duplicate]
Could a standardized ternary (base-3) system be more efficient than the binary (base-2) system? Binary is efficient for processing using logic gates, but can be bulky when using for file storage or ...
2
votes
0answers
48 views
Can you read a file as a binary number?
This is a pretty naive question, but I would like to better understand the basics of information storage on a computer. I am not concerned with the detail of how any one operating system achieves ...
3
votes
0answers
48 views
What data structure should I use for storing my data?
I am currently looking for a way in which I can store my data, and quickly look it up.
What currently seem to be the best idea is to use a hash map.
reasons:
To identify what item I am looking for, ...
0
votes
0answers
55 views
How are files managed in a filesystem?
I have recently been interested in low level computer science (as a hobby), and I have just learned about the way a computer organizes and stores information on a hard drive. I have learned the basics ...
0
votes
1answer
38 views
Creating a numbered list, divided into types, without need for shifting or re-ordering - is this a re-occuring problem
My question is not for a solution to the problem, though I do need to put thought into it but rather my question is if this conceptual problem has a name or has been addressed at already in computer ...
1
vote
0answers
491 views
How to calculate multibit trie storage size?
I wish to use a multi-bit trie structure for storing IPv4 forwarding information with a fixed stride width of 8 bits, I think this is also called a "radix of 8" (so for any IP prefix 4 levels will ...
0
votes
1answer
950 views
How is the data stored in AVL tree in a memory? [duplicate]
I have been struggling to visualize how is the AVL tree is stored in memory?
Does it store data in array or list, If so how is it connected with its child and parents.
-1
votes
1answer
90 views
Comparing the Speed of Random Number Generation to Reading Data
Imagine you need $n$ random numbers from a Gaussian distribution with $\mu=0$ and $\sigma=1$. And you need to use each of these $n$ numbers $k$ times in various operations. Let's identify the numbers ...
0
votes
0answers
41 views
Should we consider number of surfaces in a disk while calculating effective data transfer rate?
Suppose a disk has
Number of surfaces: 8
Number of sectors per track: 20
Sector size: 4000B
Number of tracks: 10
It is rotating at 360 rpm.
So disk is reading data from one track at an instance....
0
votes
2answers
135 views
how does a harddisk work? block / sector [closed]
Can someone explain me the way harddisks work? :/
The size of a block is specified in the filesystem, am I right? As you can see in the picture from wikipedia, the disk is divided into circle sectors. ...
3
votes
4answers
984 views
time efficient key value store for fast lookup
Let's state a collection of key/values.
Key is an unsigned integer (0 - 2^32-1). Hense there are comparable.
Value is few bytes fixed size.
There are 4M items in the collection.
Keys are not evenly ...
7
votes
3answers
501 views
What is the minimum required storage for a sparse, depth-first octree?
For a numerical simulation framework, I use a hierarchical Cartesian grid in 3D to discretize the computational domain. I am thus looking for the most space-efficient way to store the resulting octree ...
0
votes
2answers
3k views
1 bit register with data flip flop doesn't store bit?
A 1-bit register:
Credit:
Elements of Computing Systems
by Noam Nisan and Shimon Schocken
ISBN-13: 978-0262640688
I know that the data flip flop outputs the input at the previous time step.
...
41
votes
9answers
11k views
Understanding serialization
I am a software engineer and after a discussion with some colleagues, I realized I do not have a good grasp of the concept serialization. As I understand, serialization is the process of converting ...
0
votes
1answer
199 views
Most Efficient Way to List All $n$-bit Permutations
Suppose we are tasked with expressing a randomized list of all numbers up to but excluding $2^n$ (ie. a random list of all n-bit numbers). What are some efficient ways to do such a listing using as ...
0
votes
0answers
79 views
Maximum number of disks in RAID with parity?
From what I understand, to implement RAID 5, one would need a minimum of 3 disks, where 2 would be for data storage, and the third would be for the parity. But what is the maximum number of disks one ...
-1
votes
1answer
169 views
Latency vs IOPS. How can one conflict with the other?
I was reading about latency and IOPS, and I understood what they mean and their significance in the storage world. But what I do not understand (many places it is mentioned) is that how can the ...
0
votes
0answers
41 views
How storage affect if we use tertiary language? [duplicate]
as we uses binary language in all the computer systems around us which consist of 0s and 1s (Off and On) bits. Let assume that someone is developing a computer system based on tertiary system -1, 0, 1 ...
1
vote
1answer
378 views
How are the number of bytes less than the number of pixels in an image?
Lets take, for example this jpeg image here
The image there is 400 x 300, or 120000 pixels and The file size of the image (on my computer) is shown to be 65171 bytes.
This means the computer stores ...
3
votes
1answer
111 views
Is there a name for “density” of information?
If we compare multimedia and text, if we have n bytes of text and compare it with n bytes of video, then we would be likely to think that n bytes of text is "more" information than n bytes of video ...
3
votes
0answers
116 views
Representing Computations on Transcendental Numbers
Consider the set of transcendental numbers that are not compressible to a finite base-2 representation. How can I compute multiples (more generally, any algebraic computation) of one of these numbers,...
-3
votes
1answer
78 views
Determining HD Content [closed]
A storage system has 6 hard drives set up as RAID 5, where HD 6 is the parity disk using odd parity. One day, the system crashes due to failure of HD4. During recovery, we find out that HD1 stores ...
1
vote
1answer
162 views
How can I formalize key value stores with set theory?
I'm currently developing a simple key-value NoSQL store and want to build its formal model. I found article about key value formalisation with category theory, but I'm interested are there some works ...
0
votes
1answer
506 views
Why do computers use binary, instead of ternary, or some other logic system? [duplicate]
In binary a unit (bit), can store 2 separate values.
if you have ternary, then a unit can store 3 separate values.
why then don't computers use higher bases, for example in ternary you could have 3 ...
1
vote
2answers
108 views
Why don't hard drives actually delete data?
As far as I understand it, when you delete a file from trash/recycle bin the file isn't actually erased from memory but is instead marked as being okay to be over written.
So, my question is as to ...
5
votes
4answers
400 views
A “triangular” data structure for commutative relationships
A multiplication table is symmetric over a diagonal, so only about $n^2/2$ of the elements in an $n \times n$ multiplication table contain unique information. Same goes for addition tables. In fact, ...
0
votes
1answer
173 views
How to store factorials? [closed]
Can someone help me to store the factorial of large numbers such as 100! efficiently?
UPDATE: obviously, storing the argument rather than the factorial digits themselves achieves a significant saving....
4
votes
0answers
62 views
Extending the causal memory model to wide-area distributed storage systems
In the seminal paper "Causal memory: definitions, implementations, and programming", distributed causal memory is defined to ensures that all the processes in a system agree on the relative ordering ...
1
vote
1answer
53 views
Why is data stored on a flash disk irretrievable if the memory chip is cracked? [closed]
All data recovery companies, regardless of skill, unanimously say that if the memory chip of a device has just a hair line crack, data recovery is impossible. Not unlikely, not expensive, but ...
1
vote
2answers
73k views
What is the difference between storage media and storage devices [closed]
I am having a rather distressing confusion about whether storage media and storage devices are the same terms. I found on this ...
5
votes
3answers
2k views
Does the performance of matrix multiplication depend on the storage of the array?
Two matrices can be stored in either row major or column major order in contiguous memory. Does the time complexity of computing their multiplication vary depending on the storage scheme? That is, I ...
4
votes
1answer
2k views
Why do some filesystems have fragmentation and others don't?
I try to understand why fragmentation is a problem for NTFS and FAT but not when using inodes.
In all cases, files are not necessarily stored in a contiguous fashion so I don't see the problem for the ...
2
votes
1answer
5k views
SSTF disk scheduling algorithm? What if lowest seek times are equal in either direction?
Using the Shortest-Seek-Time-First (SSTF) disk scheduling algorithm (where we select a request with a minimum seek time from the current head position), what happens if the requests in both directions ...
1
vote
1answer
951 views
Processes and Segmentation
The following problem was on my final and in Gate 2006, but I don't understand how to solve it:
Different methods of memory management have different overheads:
...
2
votes
1answer
1k views
Calculate storage requirements for a data set
I have a simple problem. I can't seem to even find the right search terms to get me pointed in the direction I need to be heading.
I'm writing a bunch of integers to disk. Lot's of them.
Starting ...
